The present invention relates generally to joints formed in metal parts and to structures formed using the same.
A commonly used method of providing high strength and lightweight characteristics is to construct a structure using a cellular web extending between respective plates. The web may be typically honeycomb shaped with each honeycomb cell having a hexagonal shape. The honeycomb shapes may be formed of corrugated metal strips laterally displaced from one another and joined to have the appearance of natural honeycomb. The web is usually welded, brazed, or otherwise fastened to the face sheets.
The applications for these types of honeycomb structures are numerous. A main difficulty with the structures, however, is that they are cumbersome and inefficient to manufacture. For example, a honeycomb drum for use in the non-woven industry, e.g. to make baby diapers, has been formed using heavy aluminum castings which must be extensively machined. Framed honeycomb segments composed of cells of classic six-sided honeycomb are bolted to the machined castings and the outer diameter surface of the honeycomb is machined. A micro-etched screen is welded to the exposed outer honeycomb surface to create the desired vacuum-forming surface. The drum typically includes ribs traversing its width that may be as much 0.150xe2x80x3-0.200xe2x80x3 thick in a typical drum of about 2xe2x80x2 diameter to support loads imposed upon the drum. Because of this, the drum may weigh as much as 250 lbs., making it cumbersome for handlers.
Accordingly, there is a need in the art for lightweight cell structure that may be constructed by simple fabrication techniques.
A joint consistent with the present invention includes a first metallic member with a first opening having a body portion and extending portion. A second metallic member having a second opening is disposed in the first opening of the first member so that the second opening at least partially overlaps the body portion to create a joined opening. A bonding agent, e.g. adhesive, is applied in the joined opening so that when cured, it forms an integral part of the joint.
A slot-to-slot joint consistent with the invention includes each metallic member equipped with a slot. Each slot has a body portion and extending portion. The two members are slid together so that their respective body portions at least partially overlap to define a joined area where a boding agent may be applied. Alternatively, each member may be additionally equipped with a cutout aligned with each slot so that the cutout from the first member at least partially aligns with the body portion from the second member and vice versa.
A tab-to-slot joint consistent with the present invention includes a first metallic member with a tab having a cutout at least partially disposed within the tab. A second member has a slot that includes a body portion and extending portion. The tab of the first member is inserted into the slot of the second member so that the cutout at least partially overlaps the body portion to define a joined opening where bonding agent may be applied.
A drum laser cut from metallic sheets includes a plurality of annular members joined by a plurality of ribs via different joints such as slot-to-slot and tab-to-slot joints. A mechanical housing includes a cell structure sandwiched between first and second metallic plates. Methods of forming joints are also disclosed.